This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. With its short lifespan, genetic amenability and the availability of long-lived mutant strains, C. elegans has become one of the most attractive model systems for aging research. In a previous collaboration, we have discovered very intriguing proteomic changes in worms that are long-lived due to dietary restriction or knockdown of insulin/IGF-like signaling. An important part of these changes is related to protein turnover. We hypothesize that lifespan extension in C. elegans is supported by changes in the turnover of specific protein pools. In the proposed project, we will apply the sensitive and reliable method pulsed SILAC, to verify whether proteins that are important for somatic maintenance are turned over more rapidly in long-lived worms compared to the corresponding controls. On the other hand, we expect a compensatory decrease in the turnover of the bulk of other proteins in these long-lived animals. For the experimental setup, we will use two mutant strains with extended lifespan: daf-2 (which is an insulin/IGF receptor mutant) and ife-2 (a somatic translation initiation mutant) and one strain in which lifespan is extended by environmental manipulation and dietary restriction by food dilution. These three long-lived strains will be compared to a corresponding control strain with normal lifespan. Worm culturing, SILAC labeling and sampling will be performed in the Braeckman lab, known for its extensive experience with C. elegans culturing and aging studies. These samples will be subsequently analyzed and quantified with state-of-the-art world class technology utilizing high resolution and mass accuracy mass spectrometry technologies at PNNL.